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The present article is devoted to the issue of studying the patterns of displacement of superincumbent rock over panels of a mine obtained using advanced seismic technologies, allowing for the study of the boundaries of caving zones in the depths of rock mass. A seismic exploration has been performed in local areas of Zhomart mine responsible for the development of Zhaman-Aybat cuprous sandstone deposits in Central Kazakhstan at the stage of repeated mining with pulling of previously non-mined ore pillars and superincumbent rock caving. A 2D field seismic exploration has been accomplished, totaling to 8000-line m of seismic lines using seismic shot point. The survey depth varied from 455 m to 625 m. The state-of-the-art technologies of kinematic and dynamic analysis of wavefield have been widely used during data processing and interpretation targeted at identifying anomalies associated with the structural heterogeneity of the pays and rock mass, engaging modern algorithms and mathematical apparatuses of specialized geodata processing systems. The above effort resulted in new data regarding the location and morphology of the reflectors, characterizing geological heterogeneity of the section, zones of smooth rock displacement, and displacement of strata with significant disturbance of the rocks overlying mined-out productive pay. The potential of the application of modern 2D seismic exploration to studying an underworked zone with altered physical and mechanical properties located over an ore deposit has been assessed. The novelty and practical significance of the research lies in the determination of the boundaries of zones of displacement and superincumbent rock caving over the panels obtained using state-of-the-art technologies of seismic exploration. The deliverables may be used to improve the process of recognizing specific types of technogenic heterogeneities in the rock mass, impacting the efficiency and safety of subsurface ore mining, both for localization and mining monitoring. [ABSTRACT FROM AUTHOR]

Limited access to safe drinking water is a critical global issue, particularly in areas with inadequate infrastructure. Solar stills offer a promising alternative for such regions. This study investigates the influence of square baffles within a modified solar still design on its overall efficiency. Additionally, the integration of reflectors is explored to enhance both evaporation and condensation rates. Furthermore, the effectiveness of a paraffin wax phase change material (PCM) combined with silver nanoparticles is assessed within the modified still. Thermo-economic analyses are conducted to evaluate the economic feasibility of the proposed system. The findings demonstrate a significant improvement in distillation yield. The modified still with square baffles achieved a yield of 9800 mL/m2.day compared to 3550 mL/m2.day for the reference still, representing a 193 % increase. Moreover, incorporating the nano-PCM at an optimal configuration (25 cords) resulted in a further 265 % productivity increase for the modified still with both square baffles and reflectors. This configuration also achieved an efficiency of 63 %. Economic analysis revealed a minimal cost difference between the reference still (0.014 $/L) and the modified still with square baffles and nano-PCM (0.01 $/L). In terms of environmental impact, the modified still exhibited a lower annual CO2 emission of 28.8 tons.

Russia's Arctic shelf and, in particular, the Kara Sea shelf, is one of the unique regions in the world with enormous hydrocarbon potential; however, due to the harsh climate conditions, it has been studied unevenly. The lack of deep and parametric drilling data in the northern Kara Sea leads to numerous uncertainties in regional geological structure models and, as a consequence, in assessing the resource potential of this Arctic region. A vast number of 2D CDP seismic explorations were carried out in the northern Kara Sea. The results of these studies made it possible to refine the geological structure of the Kara Plate, substantiate the boundaries of the North Kara independent prospective oil and gas region and promising areas within it, and assess hydrocarbon resources. [ABSTRACT FROM AUTHOR]

Munia birds (Lonchura spp.) are pests that attack paddy plants during the reproductive phase. The traditional methods of controlling birds are considered less effective because birds can adapt to the tools used. This study aimed to determine the effectiveness of a metallic light-based bird-repellent prototype to reduce paddy yield loss. The experiment was conducted in Cileles Village paddy fields, Jatinangor Subdistrict, Sumedang Regency, West Java Province, Indonesia. The effectivity of the prototype was tested by measuring the effective distance (m2), counting the frequency of bird visits (number of visits), bird populations, and the level of paddy damage (%), and paddy yield (kg/ 64 m2). The result of the experiment showed that 3 m was an effectual deterrent factor for the prototype, thus the tool can protect paddy plants with an area of 28.26 m2. The frequency of bird arrivals in the treatment was 22.25 times, compared to 61.25 times in the control; the bird population in the treatment was 48.25 birds, while the control was 108.75 birds; the level of damage to paddy panicles in the treatment was 10.11%, compared to 37.79% in the control; and the production of paddy yield with the repellent was higher (33.37 kg/ 64 m2) than the control (23.09 kg/ 64 m2). This innovative prototype was potentially able to deter bird pests in the paddy fields. [ABSTRACT FROM AUTHOR]

Energy that can be obtained from natural resources and constantly replenished by nature is called "renewable energy". To harness solar energy and convert it into electricity, a device known as a solar panel is utilized. However, solar panels encounter certain drawbacks, including reduced efficiency as the panel temperature rises and the partial absorption of sunlight due to its reflection by the top glass layer. This study aims to optimize solar panel efficiency by innovatively integrating a cooling system with water treatments and an aluminum foil reflector to enhance energy output. The study focused on a 700 mm × 510 mm × 30 mm monocrystalline solar panel. Initial efficiency improved significantly after implementing the cooling and reflector system. Based on measurement data, incorporating the reflector, revealed an average temperature of 61.3°C and solar radiation of 871.10 W/m². The cooling duration of 40.64 seconds was achieved with a water pump flow rate of 0.29 lt/s. Notably, the combined approach yielded substantial efficiency enhancements, with the solar panel reaching peak efficiency levels of 10.36%. [ABSTRACT FROM AUTHOR]

The hybrid system integrating a solar photovoltaic (PV) module and a passive single-slope solar still (PSSSS) has been designed and tested. The PV module, equipped with mirror reflectors and automatic water cooling, is aimed to enhance the solar radiation input and reduce the module surface temperature. Preheated feedwater maintained a constant basin water level in the PSSSS. April and May 2022 experiments revealed a 12.5% daily average efficiency for the PV module in the hybrid setup, marking a 21.6% improvement over conventional photovoltaic module. The PSSSS in the hybrid configuration yielded 25% more distilled water (2.7 L/day) than a standalone solar still. The hybrid system achieved maximum overall efficiencies of approximately 61.5% and 58.5% in April and May 2022, respectively. [ABSTRACT FROM AUTHOR]

The ability of bifacial photovoltaic (PV) to absorb solar radiation on either side increases the energy output. Reflectors increase the albedo and help to increase the performance. Reflectors face discoloration and degradation with time and they increase the overall implementation cost of bifacial PV systems. However, the cost of reflectors can be reduced by using nonbiodegradable waste as reflectors. They also increase the reusability of nonbiodegradable waste materials and reduce their impact on the environment and the cost of reflectors. To make a comprehensive analysis, an investigative approach of energy, exergy, economic, exergoeconomic, enviroeconomic, and energy payback time (6E) analysis is conducted for the bifacial PV module with nonbiodegradable waste, such as polyvinyl chloride (PVC) flex, polystyrene foam, and aluminum foil as reflectors in this study. The 6E analysis includes the analysis of energy, exergy, economic, exergoeconomic, enviroeconomic, and energy payback time factors. The analysis results indicate that the PVC flex as a reflector enhances the bifacial PV performance better compared to polystyrene foam and aluminum foil. The average power, average energy efficiency, and average exergy efficiency of bifacial PV with PVC flex reflector observed during the study are 224 W, 27%, and 31%, respectively. The use of nonbiodegradable waste also has a positive impact on the environment and economy. [ABSTRACT FROM AUTHOR]

Solar energy storage is essential in renewable energy systems, considering that solar energy is a periodic energy source that depends on time, so the intensity of solar radiation changes from time to time. Therefore, solar energy systems require storing energy to save it during the night periods or on cloudy days. The current solar heater designs are not feasible and ineffective unless energy storage is utilized (energy retention). The present research addresses improving the home solar water heater (SWH) performance under the atmosphere of Iraq. This study improves the thermal performance of a solar water heater integrated with a thermal storage tank using materials storing heat to achieve the most extended possible period of receding solar radiation. The SWH system performance was experimentally tested in Tikrit-Iraq. Several experiments were performed from 8:30 am to 16:30 hours in February 2022 with a water mass flow rate (\dot{m_w}) of (0.016 kg/s) for the circulation system and with a thermal load on the hot water tank (\dot{m_{th.L}}) of (0.0066 kg/s) for the two porous medium design cases (with and without solar reflectors). The results manifested that the maximum daily thermal efficiency (ηo) of the SWH system was 36.40% for design case 2 (with porous media and reflectors) at a (0.006 kg/s) thermal load compared to the case 1 (with porous medium and without reflectors) of 32.21%. At the same load, the outcomes elucidated that the overall thermal efficacy of the SWH regime in the convection presence provided the uppermost value utilizing porous media and reflectors. Also, the outcomes of the present investigation were compared with the preceding study, and the comparison outcomes were better than the present design circumstances.

In this article, a project of portable photoelectric and photo thermal devices with a power of 60W based on crystalline silicon photoelectric batteries for the production and use of electricity and hot water for household needs in the rural areas of the republic was created. This natural experiment served two purposes. The first is to determine the optimal type for the climate when the various types of PVs available in the local commercial market are used in hot climates. Second, the results of determining and comparing the changes in parameters and energy efficiency of PV and PVT with the same base and capacity at the same time under the same conditions are presented. The results of the study of the parameters that increase their effectiveness have been considered. Special attention is paid to modern components and equipment so that these devices are relatively compact and convenient to operate and control occurs easily.

The objective of this study was to enhance the performance of hemispherical solar stills (HSS) through experimental investigations utilizing various types of sand beds as thermal storage materials. The research examined the influence of sand type (yellow and black) and sand bed heights (1, 2, and 3 cm) on the efficacy of HSS. Additionally, the study explored the effects of external reflectors and a vapor extraction fan on the performance of sand-based HSS. The experimental results indicated that HSS using black sand demonstrated superior performance compared to other operating conditions in terms of both productivity and efficiency. Particularly, the most significant improvement in performance for the black sand hemispherical solar still (BSHSS) was observed when employing reflectors and a fan with a sand bed height of 1 cm, resulting in a substantial 154% increase in production, where the production for hemispherical SS and BSHSS + fan and reflectors was 4100 and 10400 mL/m2.day, respectively. Under these optimized conditions, the thermal efficiency of BSHSS + R + F reached 56%. In conclusion, an economic analysis was conducted, revealing that the cost for water treatment was $0.022 per liter for the conventional hemispherical solar still (HSS) and $0.012 per liter for the BSHSS equipped with reflectors and a condenser. These findings represent a significant advancement in enhancing the feasibility and efficiency of solar distillation systems, thereby addressing the global challenges of water scarcity and environmental sustainability.

The shortage of safe drinking water is among the issues that the globe is experiencing more and more. One of the best options for remote locations lacking in civilian infrastructure is solar stills. The primary goal of the current study was to determine how using different designs of longitudinal and square baffles in the basin of the cords pyramid solar still (CPSS) affects its performance with and without silver nanoparticles. In addition, raising the levels of evaporation and condensation was achieved by introducing reflectors and vapor extraction with CPSS. Also, the thermo-enviro-economic analyses were tested to obtain the profitability of the proposed system. The results reported that the distillation of CPSS with lined baffles (CPSS-LB) and PSS was 9150 and 3500 mL m−2 day, correspondingly, with improvement of 162%. Moreover, the distillation of CPSS with square baffles (CPSS-SB) was 193% greater than PSS, with the aggregated distillation of CPSS-SB and PSS being 9800 and 3350 mL m−2 day, accordingly. Also, utilizing reflectors with CPSS-SB increased the output over the PSS by almost 233% (3600 mL m−2 day for PSS versus 12,000 mL m−2 day for CPSS-SB), while the fan and reflectors increased production of CPSS by roughly 257% (3550 mL m−2 day for PSS and 12,650 mL m−2 day for CPSS with fan and reflectors). Besides, the CPSS-SB with Ag increased productivity over PSS by 274% (3200 mL m−2 day for PSS vs 11,970 mL m−2 day for CPSS-SB with Ag). Moreover, with the use of Ag nanoparticles, the productivity increase of CPSS with reflectors and fan was 274%, with a thermal efficiency of approximately 68.8% at 25 cords, while with 35 cords, with the use of Ag nanoparticles, the productivity increase of CPSS with reflectors and fan was 282% (3100 mL m−2 day for PSS and 11,850 mL m−2 day for CPSS), with a thermal efficiency of approximately 70%. For PSS and CPSS-SB-Ag, the reported expenses of the treated water were 0.0141 and 0.01 $L−1, correspondingly. The environmental parameter of CPSS-SB-Ag was annual CO2 emissions of 28.7 tons. Additionally, the enviroeconomic parameter (Z′) for CPSS and CPSS-SB-Ag was 370 and 420 per year for 340 operating days and two decades, respectively. [ABSTRACT FROM AUTHOR]

One of the best solar distillers in terms of productivity is the stepped solar distiller, but it suffers from a lack of productivity commercially. This study proposes some amendments to enhance its performance utilizing nano-improved paraffin wax as a thermal storing material and reflecting surfaces. As a result, two solar distillers were fabricated and tested simultaneously under the same weather conditions: one is the conventional distiller, and another is the modified stepped distiller. Results revealed that the modified stepped distiller gave better performance than the conventional distiller, both in terms of productivity and efficiency. For example, the yield of the modified stepped distiller was improved by 55.6% compared to that of conventional distiller. Moreover, when utilizing the thermal storing material with the modified stepped distiller, its yield was augmented by 77.88% over conventional distiller. Furthermore, the productivities of conventional distiller and modified stepped distiller with thermal storing material and reflecting surfaces are 2400 mL/m².day and 6750 mL/m².day, severally with an betterment of 181.25%. In this case, the efficiency of modified stepped distiller was 46.4%. [ABSTRACT FROM AUTHOR]

When it comes to renewable energy, solar water heaters are among the fastest-growing technologies. Comparatively speaking, integrated collector-storage solar water heater systems cost less than other solar water heater designs. Therefore, both the construction and the operation of a combined collector-storage solar water heater are quite straightforward. The integrated storage solar collector coupled with reflectors has been experimentally investigated. The reflectors were insulated from the back side when working during the day hours and as insulated cover during the night hours. While comparing the combined collector-storage solar water heater with and without insulated reflectors, the results showed that the insulated reflectors increased the thermal efficiency by 23%. Furthermore, on the coldest day, the stored water reached a high of 82 degrees Celsius, though it was only 46 degrees Celsius that same morning.

In order to maintain access to freshwater resources in water-stressed regions, it is important to improve the performance of solar-powered desalination systems with lower cost units like solar stills (SS). However, the SS produces low productivity especially through the rainy or cloudy days due to the indirect diffused beams. Therefore, the main aim of this study is to increase the yield from brackish/seawater via a solar still operating with renewable energy sources. The water depth was lowered, and thermal storage materials with different sand beds trays solar still (TSS) are used to augment the amount of yield from a SS. The effects of sandy bed height, and sand type (black and yellow) on the performance of TSS were investigated. Also, the effect of internal reflectors on the sand TSS performance was investigated. Experimental results revealed that the sandy layer (storage beds) improves the TSS production. The maximum increase in accumulated production of sandy TSS with internal reflectors was reached at sand beds height of 1 cm and black sand. In this case, the freshwater was heightened by 105 % over CSS.

This study describes an ongoing intense earthquake swarm in the crust of the northeastern Noto Peninsula, Japan, that began around the end of 2019. Fluid movement related to volcanic activity is often involved in earthquake swarms in the crust. However, no volcanic activity has occurred in this region since the Middle Miocene (15.6 Ma). This study investigates the cause of this earthquake swarm based on the spatiotemporal evolution of earthquake hypocenters and seismic reflectors. The hypocenter relocation of 10,940 earthquakes (M > 1) reveals that they are all crustal and migrated upward, activating a complex network of faults at depths shallower than 20 km. The initiation of this earthquake swarm occurred at a locally deep depth (z = 17 km), and the local hypocenter distribution shows a characteristic circular pattern. We find a distinctive S‐wave reflector in the immediate vicinity. A low‐velocity anomaly exists below the reflector, and a high helium isotope ratio and a low‐gravity anomaly were observed at the surface. These observations suggest that the current seismicity is associated with fluids released by ancient or possibly unrecognized modern magmatic activity, although no volcanic activity has been documented in this area for 15 million years. Significant crustal deformation was observed during this swarm and is probably related to the fluid movement and aseismic deformation that contributed to this earthquake swarm. The strongest M5.4 earthquake (as of October 2022) occurred near the migration front on the largest planar structure, leaving the shallow extension unruptured. Plain Language Summary: An intense earthquake swarm is currently occurring in the crust of the northeastern Noto Peninsula, Japan. Fluid movement related to volcanic activity is often involved in earthquake swarms in the crust, but no volcanic activity has occurred in this region since the middle Miocene (15.6 Ma). We investigate the cause of this earthquake swarm using precisely determined earthquake locations and seismic reflectors. We find that the earthquakes moved from deep to shallow depths via many planes, similar to earthquake swarms near volcanoes. The strongest M5.4 earthquake occurred near the migration front on the largest planar structure. Further earthquakes may be possible in the shallow part of this fault. We find a distinctive S‐wave reflector, suggesting a fluid source, in the immediate vicinity of the initiation point of this swarm. The local hypocenters show a circular pattern similar to the ring fault that forms above the magma reservoir. These observations may indicate that the current seismic activity is being impacted by fluids related to ancient or new hidden magmatic activity. The present results suggest that hidden magma‐induced structures and fluids can generate earthquakes even in areas where no volcanic activity has been observed for over 10 million years. Key Points: An intense seismic swarm continues in a non‐volcanic region, with upward earthquake migration through a complex network of faultsA deep S‐wave reflector located near the seismicity initiation point and above the low‐velocity anomaly may represent a fluid sourceThe significant surface deformation observed during this swarm was caused by aseismic deformation activated by fluid migration [ABSTRACT FROM AUTHOR]

In this paper, the electrical and thermal performance of hybrid photovoltaic (PV/T) system works with an active cooling open water cycle has been improved. Experimental tests were conducted on the (PV/T) of two cases (with and without reflectors) and the reference photovoltaic (PV) in Iraq - Samarra located at latitude (34.26°N) and longitude (43.89 °C). Several experiments were carried out during June 2021 with a (0.014 kg/s) mass flow rate. Results manifested that the maximum daily electrical, thermal and overall PV/T collector efficiency with reflectors were 10.2%, 82.3%, 92.5%, respectively, with the highest improvement in the electrical power (EP) of 69.4%. This technique has proven its effectiveness in the hot climate that Iraq enjoys (suffers), and that the water jets played their role in decreasing the temperature of the hybrid panel despite the increase in the concentration of solar radiation throughout the presence of reflectors. [ABSTRACT FROM AUTHOR]

In order to maintain access to freshwater resources in water-stressed regions, it is important to improve the performance of solar-powered desalination systems with lower cost units like solar stills (SS). However, the SS produces low productivity especially through the rainy or cloudy days due to the indirect diffused beams. Therefore, the main aim of this study is to increase the yield from brackish/seawater via a solar still operating with renewable energy sources. The water depth was lowered, and thermal storage materials with different sand beds trays solar still (TSS) are used to augment the amount of yield from a SS. The effects of sandy bed height, and sand type (black and yellow) on the performance of TSS were investigated. Also, the effect of internal reflectors on the sand TSS performance was investigated. Experimental results revealed that the sandy layer (storage beds) improves the TSS production. The maximum increase in accumulated production of sandy TSS with internal reflectors was reached at sand beds height of 1 cm and black sand. In this case, the freshwater was heightened by 105 % over CSS. [ABSTRACT FROM AUTHOR]

Harvesting freshwater from saline and seawater using solar energy has proven a significant impact in recent times. The present study aims to investigate the performance of the solar desalination system by incorporating glass reflectors, heat storage media, and a thermoelectric cooling system with a single-basin-type distiller. Accordingly, the objective of the study is to improve the performance of the solar distiller in terms of freshwater production and efficiency compared to a conventional setup. Moreover, the designed unit was tested under the environment of the Western part of India (Mehsana—23.5880° N, 72.3693° E) for 19 days in the months of May and June 2022. The maximum daily productivity observed during the day was 2.5 l at an average solar radiation of 1200 W/m2, which was 1.23 times higher than its conventional counterpart. Similarly, the energy efficiency showed a maximum improvement of 23.73%. At the middle of the day, i.e., maximum performance condition, the exergy efficiency was doubled with current modifications. Solar radiation and ambient temperature were found to be the most critical parameters that influence performance. Modifications also increase the % off sunshine hour productivity compared to sunshine hour from ~ 10 to 11% to ~ 20.8 to 24%, respectively. The cost of water distillation for the proposed solar still was found as 0.037 $/l/m2,s and the payback period was estimated as 2.27 years. The overall results indicate the positive influence of the modifications; hence, this type of setup is feasible for implementation on the field in harsh and coastal line areas. However, modified single-basin solar still needs extended field study to realize the full potential of the modifications. [ABSTRACT FROM AUTHOR]

When it comes to renewable energy, solar water heaters are among the fastest-growing technologies. Comparatively speaking, integrated collector-storage solar water heater systems cost less than other solar water heater designs. Therefore, both the construction and the operation of a combined collector-storage solar water heater are quite straightforward. The integrated storage solar collector coupled with reflectors has been experimentally investigated. The reflectors were insulated from the back side when working during the day hours and as insulated cover during the night hours. While comparing the combined collector-storage solar water heater with and without insulated reflectors, the results showed that the insulated reflectors increased the thermal efficiency by 23%. Furthermore, on the coldest day, the stored water reached a high of 82 degrees Celsius, though it was only 46 degrees Celsius that same morning. [ABSTRACT FROM AUTHOR]

• Augmented performance of solar still was evaluated via integrating evaporation and condensation enhancers. • Synthetic nanocomposites were developed, characterized, and used with different concentrations. • Thermo-economic performance was investigated compared to conventional solar still. • Productivity, energy efficiency, and average exergy efficiency augmentations reached 113.72, 96, and 167.62 %, respectively. This work aimed to develop the thermo-economic performance of solar still (SS) via various additives. On the one hand, to improve the thermophysical properties of the basin saline water, two nanocomposites were utilized in the modified SSs (MSSs). In MSS1, chitosan @ graphene oxide (Cs@GO) was used, whereas chitosan @ nickel oxide (Cs@NiO), was provided in MSS2. The concentration influence on the yield was investigated considering three ratios (0.1, 0.2, and 0.3 wt%). The selected concentration (0.3 wt%) was used for the upcoming cases being better than others. At this weight ratio, the yield was augmented by 72.7, and 57.5 % for MSS1, and MSS2, respectively, compared to CSS. In the first case (Case I), a glass lid cooling unit was attached to the MSSs to boost the condensation rate. In the second case (Case II), top and bottom external reflectors were fixed on the MSSs. Then, Case III contained both cover cooling and reflectors. In addition to these enhancers, ultrasonic atomizers were placed on the basin of MSSs in Case IV. In each experiment, both MSS1 and MSS2 were simultaneously compared to conventional SS (CSS). All cases showed good thermo-economic performances. The best performance was obtained, especially in terms of yield, from MSS1 in Case IV, at which the production, energy, and exergy efficiencies were improved by 113.72, 96, and 167.62 %, respectively. [ABSTRACT FROM AUTHOR]

A study has created a solar pond model. The pond's performance in terms of heat storage and electric power generation using TEG is analyzed using this model. The impact of various parameters, such as covering the pond's surface with plastic and using reflectors to focus on the intensity of solar radiation, will be investigated. A pyramidal pond with a base size of 0.64 square meters was used to validate the model. And it has a 6.25 square meter surface area. There's also a 1.35-meter depth. The walls are inclined at a 60-degree angle. TEG was also used to determine the pond's electrical capacity. The addition of a plastic cover and reflectors enhanced the efficiency of the pond's operation from 12.1% to 27.5%, according to the findings. At a lower layer temperature of 60 degrees Celsius, the electrical capacity reached 104 watts with a TEG operating efficiency of 8.9%. [ABSTRACT FROM AUTHOR]

This article intends to theoretically propose and investigate the construction of a solar pond with a salinity gradient and the generation of electrical energy from it using a thermoelectric generator. It is possible to gradually add salt (magnesium sulfate salt) to the lower layer, increasing the quantity of thermal energy supplied to the pond. According to the theoretical findings, increased heat storage in the pond's bottom layer is enhanced by the addition of salt, and reflecting mirrors help to raise the quantity of solar radiation that is directed at the pond's surface, increasing the amount of thermal energy that is absorbed through the layers of the pond. Thermal energy losses are decreased by the plastic cover that has been applied to the pond's surface. When salt, a cover, and mirrors were added to the conventional pond, the amount of useable energy increased from (2 kilowatts) to (20 kilowatts), and these modifications helped the pond's thermal efficiency rise from (5 percent) to (28.4 percent). TEG Electric Efficiency was 12% at a temperature of 65°C and a mass flow rate of 2 L/min. [ABSTRACT FROM AUTHOR]

Nature has naturally desalinated water for centuries through the process of solar heating, where oceanic water transforms into vapor and then returns to Earth as freshwater precipitation. Freshwater is vital for sustaining life, but growing populations, industrial expansion, and increased agricultural production have created a rising demand for it. Desalination has emerged as a potential solution to address water scarcity. Existing desalination technologies fall into two categories: single-phase processes like reverse osmosis and electro-dialysis, and phase-change processes such as distillation and solar stills. While single phase processes provide freshwater, some rely on non-renewable fossil fuels for energy, indirectly contributing to greenhouse gas emissions. Solar distillation, in contrast uses renewable energy from the sun, offers a promising and sustainable alternative for freshwater production. Solar stills employ shallow water basins within enclosed structures, as moisture collects on the interior surface of the glass cover, cooled by natural airflow. In this study, two 250 X 250 mm2 single slope solar stills were designed, one conventional and the other modified with nanofluids and reflectors. The experiment assessed their performance in Hyderabad’s typical climate, with a glass cover slope of 17.45°. Both stills operated with a 1 cm water depth (500 ml) to observe the water distillate output. Readings were recorded for two different nanofluid concentrations (considering 0.08% and 0.1% of Cerium Oxide nanoparticles by volume mixed with water) allowing for a comparison of their cumulative hourly yields and effectiveness in increasing freshwater output.

This paper presents the design, analysis, and testing of a four states pattern reconfigurable monopole antenna intended for WLAN applications. The proposed planar monopole has two parallel parasitic elements, which are connected to the ground plane by two PIN diodes. By switching the diodes between the "ON" and "OFF" states, the function of each parasitic element can be changed from a reflector into a director. Consequently, the radiation pattern of the monopole can be reconfigured, and the direction of the main beam can be easily changed. The four states of the reconfigurable antenna can also be changed at the design stage by choosing a proper distance between the monopole and the adjacent parasitic element. The operation of the antenna is analysed, then simulated using the CST software to prove the feasibility of the proposed idea. Experimental testing of the fabricated prototype showed good agreement with the simulation results. [ABSTRACT FROM AUTHOR]

This study aims at enhancing the freshwater from saline water via stepped solar stills (SSS). Experimental work for different sand beds SSS was conducted to enhance its performance, the sand was used as thermal storage materials. The effects of sand type (black and yellow) and sandy bed height on the performance of stepped solar still (SS) were studied. Also, the effect of internal reflectors and cooling coil on the sand stepped SS performance was investigated. Experimental results revealed that the sandy layer improves the stepped SS productions. At 1 cm height of sand beds the accumulated productivity of the conventional solar still (CSS), SSS, yellow SSS and black SSS were 3,000 and 4,650; 5,150 and 5,750 mL/m2 ·d, with improvement of 55%, 71%, and 92%, for the SSS, yellow SSS and black SSS higher than CSS. In addition, the maximum increase in accumulated production of sandy stepped SS with internal, external reflectors and cooling coil was obtained at sand beds height of 1 cm and black sand. In this case, the production of black SSS was increased by 165% over CSS with thermal efficiency 56.6%. In addition, in comparison to the CSS, the cooling system increases black SSS productivity by 31%. The environmental parameter of black SSS with vapor withdrawal and reflectors was 24 tons·CO2 /y. [ABSTRACT FROM AUTHOR]

The rapid decrease in global freshwater sources, caused by industrialization, population growth and other unforeseen circumstances, demands the necessity of effective desalination strategies. Solar stills, which provide potable drinking water by utilizing abundantly available solar energy and a direct mode of desalination, are viable solutions. However, lower productivity limits the wide range acceptability of the conventional solar stills (CSS). This work experimentally investigates the effectiveness of interfacial evaporation in solar stills by incorporating the floating absorbers. The floating absorber solar still (FSS) is compared with CSS as a benchmark. FSS involves different absorber configurations such as bare, patterned, and multiple absorbers. Further, the effect of top and bottom reflectors (external) on the FSS performance is analyzed. The application of patterned FSS enhances the productivity by 146 % and 46 % compared to CSS and bare FSS. The use of external top and bottom reflectors in patterned FSS (FSS-P-R) enhances productivity by 28 %. The accumulated water yield per day for FSS-P-R configuration is 4.46 L / m 2 with energy and exergy efficiency of 70.35 % and 5.9 %, respectively. The cost analysis estimates the cost of the produced freshwater for FSS-P-R as 0.018 $/L, recommending the deployment of the FSS with suitable modifications in remote and hot arid regions with abundant sunshine as a promising approach for alleviating the freshwater scarcity. [ABSTRACT FROM AUTHOR]

During cloudy or rainy days, a solar still (SS) cannot work in its normal state. So, improving the yield of low-cost solar-powered desalination technologies such as the SS is essential to ensuring sustained access to freshwater for remote area. This study aims at improving the potable water from saline water via stepped solar stills. Experimental work for different sand beds stepped SS was conducted to improve its performance, the sand was used as thermal storage materials. The effects of sand type (black and yellow) and sandy bed height on the performance of stepped SS were studied. Also, the effect of internal reflectors and cooling coil on the sand stepped SS performance was investigated. Experimental results revealed that the sandy layer improves the stepped SS productions. The maximum increase in accumulated production of sandy stepped SS with internal mirrors and cooling coil was obtained at sand beds height of 1 cm and black sand. The yield was increased by 136% over conventional solar still (CSS) with thermal efficiency of 54.4%. The costs of 1 L of the freshwater for black SSS and CSS were around 0.016$ and 0.026$.

This paper presents the engineering of ultraviolet (UV) reflectors made up of alternate layers of titania (TiO2) and silica (SiO2) by using the sol-gel spin coating method. The choice of these two materials is appropriate to realize the optical reflectors due to their large refractive index contrast. The formation of multilayer films of TiO2 and SiO2 are studied by field emission scanning electron microscopy (FESEM), while UV-vis spectroscopy measurement is performed to study the reflectance. By varying the number of TiO2/SiO2 stacks, we have achieved the maximum reflectance within the UV region at center wavelengths of 335 nm, 358 nm, and 367 nm corresponding to the 3-, 6-, and 9-stacks based reflectors. Finally, it is summarized that these reflectors prohibit the propagation of ultraviolet light, and therefore, promising for UV protection coating. [ABSTRACT FROM AUTHOR]

Cooking consumes a tremendous amount of energy on a regular basis. Solar energy is a very versatile and free energy source that could be used for different applications, including solar cooking. The aim this study is intended to experimentally investigate the effect of different reflectors on the performance of solar box cookers. Box-type solar cooker has been produced and tested with no reflector, aluminum foil reflectors, and mirror glass reflectors cases. Load and no-load tests have been conducted for all three reflector cases and the performances of cookers for each cases reflector have been determined. Several cooking tests was conducted in the outdoors, to investigate the thermal performance of the cooker using water as the absorbing medium. The results of the experimental demonstrate that, the cooker with three side mirror glass reflectors could reach a reasonably high temperature with better efficiency. 1.5 kg of water boiled in 51 min and its second figure of merit was found as 0.533 using mirror glass reflectors. The mirror glass reflector increases the efficiency of the experimental box-type solar cooker by 134% as compared with the cooker having no reflector. The experimental cooker with no reflector did not boil water during the testing period, so it is not recommended for cooking applications; whereas the cooker with the mirror glass reflector has been confirmed to cook most Ethiopian dishes with reasonable performance.

In solar thermal applications, the performance of a solar absorber panel with a reflector is critical. In sense, different absorbers are used to enhance thermal efficiency. In addition to this, various coatings on solar absorber panels are introduced, and the performance of the same coated panels are examined with experimental study by design of experiment concept. For the reason, this work utilized the black-chrome coating (BC) and nickel-cobalt-coating (Ni-Co) on copper solar absorber panel. The reflectors were also used to maximize the incident solar radiation on the absorber. In this experiment the process variables are flow rate, collector angle, and reflector angle and the thermal efficiency of solar panel is the response. The response surface methodology with Box Behnken design is used to collect the experimental data from experimental setup. The collected data from designed experiment are analyzed by using Analysis of Variance Table (ANOVA). From this the coating on the absorber panel and reflectors are improved the thermal efficiency up to 89.3% of the Black – Chrome solar flat plate collector than Ni-Co panel.

There is an urgent need to provide evidence that solar air heaters can be effective for heating and ventilating low-rise buildings. Solar air heaters are devices that can convert solar energy into thermal energy for moderate and low-temperature applications such as space heating, preheating, crop drying, and the food industry. However, its efficiency is low due to the low heat transfer coefficient between the absorber and the flowing air, but they are also simple to construct and operate as there is low-risk leakage of heat transfer liquids. The two main types of solar air heaters are flat plate and tube-type. To date, flat plate solar air heaters have received the most attention in the research literature, but evidence of the efficiency gains from using tube-type solar air heaters is growing. The study aims to provide up-to-date information on tube-type solar air heaters, which will help advance the development and uptake of solar air heaters. The research showed that thermal efficiency gains could be achieved by altering the design of the solar air heater including different artificial roughness geometries inside the tubes, integrating solar thermal energy systems, application of coatings or reflectors inside the solar air heaters, or using evacuated tubes and micro heat pipe array systems. This literature study showed that evacuated tubes and micro heat pipe array systems have higher thermal efficiency than other techniques. Based on the detailed discussion of various techniques for improving the thermal efficiency of solar air heaters, a new roughness geometry was proposed. [Display omitted] • Artificial roughness improves the heat transfer. • Thermal efficiency of SAH with aluminium fibres is 90.8 %. • Maximum efficiency of flat micro heat pipe array is 85 %. • Reflectors boost the solar radiation absorption by 80 %. • A new roughness geometry is proposed. [ABSTRACT FROM AUTHOR]

• The still performance was enhanced by using reflectors and woven wire mesh. • Many factors were tested such as water depth, water salinity and using wire mesh. • The percentage increase in daily thermal efficiency for the MSS raised to 45.04%. • The percentage increase in water productivity raised to 46.8 % at 1 cm water depth. • The cost per liter for the MSS decreased by 37.5% compared with the CSS. In recent years, the urgency for harnessing solar energy for water desalination has grown significantly, driven by the escalating costs and the increasing scarcity of clean water sources. Numerous research efforts were dedicated to enhance the productivity of solar still, including the thermal energy storage materials, solar concentrators, nanofluid, and more. The main objective of this research is to improve the solar still performance by using wastes of workshops and factories so, their actual cost can be assumed to be zero. The experimental setup placed at faculty of Engineering Suez Canal University. Two solar still were included: one representing the conventional and the second one is modified with internal reflectors and woven wire mesh. The performance of the stills was assessed under identical climate conditions, considering water depths of 1, 2, 3 and 4 cm using both fresh and saline water with Total dissolved Solids of 18,562 and 35643 ppm. The obtained results indicated that the incorporation of internal reflectors and woven wire mesh led to a notable percentage increase in daily thermal efficiency and accumulative productivity ranged from 42.49 % to 45.04 % and from 43.0 % to 46.8 % respectively. The economic analysis demonstrated that the cost per liter for conventional and modified solar still was about 0.0018 and 0.0011$ per liter per m2 respectively. This study's findings suggested that the integration of internal reflectors and woven wire mesh into solar stills to obtain high productivity potable water with low cost. These results align with and reinforce previous publications in this field, highlighting the potential of this approach for addressing the pressing challenges of affordable and efficient water desalination. [ABSTRACT FROM AUTHOR]

Enhancing the produced thermal energy of a flat plate thermal collector by increasing the received sunlight using reflectors is an economical solution. For this purpose, tilts optimization of four identical planar reflectors surrounding a fixed and a bi-axial tracked flat plate thermal collector in the southeast of Algeria was investigated experimentally and by simulating novel mathematical model. The findings showed that the novel tilt angles of the reflectors in the fully tracked case, which were fixed at 67° anywhere throughout the year. On the other hand, in the fixed case, they varied from one month to another. According to the simulation results, the average annual solar irradiation was increased by 64% in the stationary system without shadowing and by 111.28% in the two-axis solar tracked system. Experimental results showed that the daily average benefit ratio of incoming sunlight and the produced thermal energy for a two-axis tracked V-Trough concentrator were considerably enhanced, especially the received irradiation, and were equal to 4.25 and 2.48, respectively. However, in the fixed case, the improvements were only 1.52 and 1.33, respectively.

The kinetics of nuclear reactors is determined by the average neutron lifetime. When the inserted reactivity is more than the effective delayed neutron fraction, the reactor kinetics becomes very rapid. It is possible to slow down the fast reactor kinetics by increasing the neutron lifetime. The authors consider the possibility of using the lead isotope, 208Pb, as a neutron reflector with specific properties in a lead-cooled fast reactor. To analyze the emerging effects in a reactor of this type, a point kinetics model was selected, which takes into account neutrons returning from the 208Pb reflector to the reactor core. Such specific properties of 208Pb as the high atomic weight and weak neutron absorption allow neutrons from the reactor core to penetrate deeply into the 208Pb reflector, slow down in it, and have a noticeable probability to return to the reactor core and affect the chain fission reaction. The neutrons coming back from the 208Pb reflector have a long ‘dead-time’, i.e., the sum of times when neutrons leave the reactor core, entering the 208Pb reflector, and then diffuse back into the reactor core. During the ‘dead-time’, these neutrons cannot affect the chain fission reaction. In terms of the delay time, the neutrons returning from the deep layers of the 208Pb reflector are close to the delayed neutrons. Moreover, the number of the neutrons coming back from the 208Pb reflector considerably exceeds the number of the delayed neutrons. As a result, the neutron lifetime formed by the prompt neutron lifetime and the ‘dead-time’ of the neutrons from the 208Pb reflector can be substantially increased. This will lead to a longer reactor acceleration period, which will mitigate the effects of prompt supercriticality. Thus, the use of 208Pb as a neutron reflector can significantly improve the fast reactor nuclear safety.

In this study, the effect of incorporating turbulators and external mirrors into a newly single pass Solar Air Heater (SAH) was investigated experimentally. Aluminium cans were stacked over the absorber plate and used as turbulators to enhance the heater efficiency. The external mirrors are utilized to improve energy input to the SAH. The effect of external bottom and top mirrors on the SAH performance is studied. Three models of absorbing plates had been tested after designing them. The first one is a flat plate without cans (turbulators), the second one is a flat plate with cans in aligned arrangement configuration and the third one is flat plate with cans in staggered arrangement configuration. A comparison between the efficiency of the modified SAHs air heaters with and without reflectors and the conventional SAH were carried out. In addition, guide vanes were attached to the inlet of a heater for ensuring better distribution of air above the absorber surface. Typical ranges of air Mass Flow Rate (MFR) are employed from 0.02 to 0.05 kg/s. Results showed that the maximum daily efficiency of the proposed SAHs was about73.4% at 0.05 kg/s for staggered heater with external reflectors and guide vanes.

• Outdoor exposure in a coastal site were used to study the corrosion phenomena of glass solar reflectors. • Edge corrosion was the most dominant phenomena due to the presence of salts and moisture. • Corrosion progress was faster for paint free lead samples, lower paint thicknesses, less paint coatings layers and unshaped edges. • The resistance of a new composite support structures replacing the metallic structures was very poor due to the fixing glue degradation. Corrosion is among the most observed phenomena that threaten the profitability of concentrated solar thermal power plants and constitutes a real risk factor for metallic materials. Solar reflectors are between the impacted materials by corrosion because they are composed of metallic reflective layers that can easily be oxidized in air. To avoid this, paint systems could be applied in the back of the reflective layers as a barrier, that prevents the diffusion of corrosive elements to the metal layer. Metallic structures that support those reflectors can also be easily corroded and are replaced with composite structures that are not affected by corrosion. However, the durability of the paint protection systems and the composite structures must be inspected to ensure their effectiveness in protecting solar mirrors against corrosion, since they are found in sites that are often characterized by arid conditions, which affects corrosion protection solutions. This work is devoted to study the corrosion aspects and the parameters that affect the resistance of the protection systems of glass solar mirrors and solar mirrors fixed on composite structures by the use of a real outdoor exposure facility on a coastal site. The results show the important role of the paint coating layers number on the protection against corrosion. Also, the role of edge protection and shape were highlighted. Solar mirrors fixed on composite structures show a weak resistance because of the degradation of the fixing glue which creates areas of retention of salts and moisture that cause an aggressive corrosion of the metal layers. [ABSTRACT FROM AUTHOR]

Recently, a lot of research has been carried out on different techniques to improve the performance of microstrip patch antenna (MPA). Here, we have overviewed and summarized various techniques which has been invented in past to improve the gain and of the MPA. The addition of frequency selective surface (FSS), metallic reflectors, metamaterial, parasitic patches, air gap, superstrate, shorting pins, defective ground structure and partial substrate removal are some known techniques to improve antenna gain. This paper helps to decide the best technique of gain improvement for MPA. [ABSTRACT FROM AUTHOR]

The present study presents an enhancement in wick solar stills performance depending on using different aspect ratios with the same project area and wick materials, glass cover cooling, and external reflectors after practical knowledge of the best wick material type and dimensions. The proposed three stills (A), (B), and (C) have evaporation area dimensions of 1 × 0.85, 1.5 × 0.57, and 2 × 0.425 m2, with an aspect ratio of 1.18, 2.63, and 4.71, respectively. The results revealed that the solar still with medium dimensions set has the best performance. Also, adding a top and bottom reflector to type (B) solar still with cotton cloth wicks increased the freshwater productivity and energy efficiency by 37.99 and 39.96%, respectively, compared to type (A) solar still with cotton cloth wicks. Moreover, the cost of one liter of freshwater distillate was decreased by 1.82%. Applying glass cover cooling on type (B) solar still with cotton cloth wicks increased the freshwater productivity and energy efficiency by 30.59 and 33.13%, respectively, compared to type (A) solar still with cotton cloth wicks. Furthermore, we have a decrement in the cost of one liter of freshwater distillate by 7.69%. Moreover, adding reflectors and cover cooling together to wick solar still increased the freshwater productivity and energy efficiency by 52.36 and 58.5%, respectively. On the other hand, the cost per liter of freshwater was reduced by 9.8%. [ABSTRACT FROM AUTHOR]

Investigation of IR light emitting diodes (wavelength 850 nm) based on AlGaAs/GaAs heterostructures with multiple quantum wells in the region generating radiation grown by the MOCVD technique has been carried out. Post-growth technologies for removing the substrate and for transfer the heterostructure on an alien carrier with an optical reflector have been developed. Technological regimes for fabricating the reflector have been optimized, and the increase of the IR radiation reflection coefficient up to 92–93% has been achieved. Light-emitting diodes with the external quantum efficiency 28.5% have been fabricated. [ABSTRACT FROM AUTHOR]

This study describes a 3D ray tracer model for analysis of a small-scale solar concentrating system where thermal heat is collected for cooking purposes. Emitted sun rays were traced from the source through all reflections until they intercepted with the receiver or were lost. The algorithm of the ray tracer and its implementation in MATLAB is clearly described. The ray tracer was programmed to contribute to the development of small-scale concentrating solar energy systems with integrated heat storage units. The ray tracer was demonstrated for selected cases where continuous reflecting surfaces and flat mirror-tiled surfaces were compared. Off-focus sensitivity analysis was shown and this could provide guidelines for the required solar tracking accuracy. The flux distribution on the absorber was analysed and found to be concentrated on a small area on the target for continuous reflecting surfaces and having high intensities. However, for reflectors with mirror tiles, an elongated image was formed centred on the focal point with low intensities. Small misalignment of the reflector in the order 0.2° had minimal impact on the interception ratio, but any further increase in the tracking errors caused a sudden drop in the interception ratio to zero. Results showed that there is close agreement in flux distribution and the tracking error impact on interception ratio, when compared with the literature. This model could be a useful tool when designing the reflection and absorption components of solar concentrators for complex systems with several components in a non-symmetric 3D arrangement.